Comment 8 for bug 2042357

amd64
-----

vm

 lxc launch --vm -c limits.cpu=2 -c limits.memory=2GiB ubuntu-daily:noble noble-vm
 lxc shell noble-vm

 # uname -rv
 6.5.0-9-generic #9-Ubuntu SMP PREEMPT_DYNAMIC Sat Oct 7 01:35:40 UTC 2023

kdump-tools

 sudo apt update && apt install -y linux-crashdump # No, Yes
 sudo sed 's/crashkernel=[^" ]\+/crashkernel=512M/' -i /etc/default/grub.d/kdump-tools.cfg
 sudo update-grub && sudo reboot

 ...

 # dmesg | grep 'crashkernel.*RAM'
 [ 0.018756] Reserving 512MB of memory at 816MB for crashkernel (System RAM: 2043MB)

 # kdump-config status
 current state : ready to kdump

crashdump

 # echo c >/proc/sysrq-trigger

 ...

 # find /var/crash/
 /var/crash/
 /var/crash/kdump_lock
 /var/crash/kexec_cmd
 /var/crash/202311081257
 /var/crash/202311081257/dmesg.202311081257
 /var/crash/202311081257/dump.202311081257
 /var/crash/linux-image-6.5.0-9-generic-202311081257.crash

debug symbols

 dpkg -l | awk '$2 ~ /linux-image-[0-9.-]+-generic/ { print $2, $3}' \
   | while read pkg version; do \
       dbgpkg="linux-image-unsigned-${pkg#linux-image-}-dbgsym"; \
       arch=$(dpkg --print-architecture); \
       wget "https://launchpad.net/ubuntu/+archive/primary/+files/${dbgpkg}_${version}_${arch}.ddeb"; \
     done

 ar p linux-image-unsigned-*-dbgsym_*.ddeb data.tar.xz | tar xJ --wildcards './usr/lib/debug/boot/vmlinux-*-generic'

crash (old)

 # dpkg -s crash | grep Version:
 Version: 8.0.2-1ubuntu1

 # crash ./usr/lib/debug/boot/vmlinux-*-generic /var/crash/*/dump.*
 ...
 crash: invalid structure member offset: module_core_size
        FILE: kernel.c LINE: 3781 FUNCTION: module_init()

 [/usr/bin/crash] error trace: 558bf515829f => 558bf4dd7efc => 558bf4e64bff => 558bf4eef301

crash (new)

 sudo add-apt-repository -y ppa:mfo/noble-crash-v2 && sudo apt install -y crash

 # crash ./usr/lib/debug/boot/vmlinux-*-generic /var/crash/*/dump.*
 ...
 please wait... (determining panic task)
 WARNING: active task ffff93c084ed0000 on cpu 0 not found in PID hash

       KERNEL: ./usr/lib/debug/boot/vmlinux-6.5.0-9-generic
     DUMPFILE: /var/crash/202311081257/dump.202311081257 [PARTIAL DUMP]
  CPUS: 2
  DATE: Wed Nov 8 12:57:51 UTC 2023
       UPTIME: 00:01:42
 LOAD AVERAGE: 0.28, 0.18, 0.07
        TASKS: 3
     NODENAME: noble-vm
      RELEASE: 6.5.0-9-generic
      VERSION: #9-Ubuntu SMP PREEMPT_DYNAMIC Sat Oct 7 01:35:40 UTC 2023
      MACHINE: x86_64 (2495 Mhz)
       MEMORY: 2 GB
        PANIC: "Kernel panic - not syncing: sysrq triggered crash"
   PID: 4488
      COMMAND: "bash"
  TASK: ffff93c084ed0000 [THREAD_INFO: ffff93c084ed0000]
   CPU: 0
        STATE: TASK_RUNNING (PANIC)

 crash> bt
 PID: 4488 TASK: ffff93c084ed0000 CPU: 0 COMMAND: "bash"
  #0 [ffffa9c500d0bb38] machine_kexec at ffffffff9dcafa3b
  #1 [ffffa9c500d0bb98] __crash_kexec at ffffffff9de133f3
  #2 [ffffa9c500d0bc60] panic at ffffffff9dcf60e4
  #3 [ffffa9c500d0bce0] sysrq_handle_crash at ffffffff9e6a4b5a
  #4 [ffffa9c500d0bcf0] __handle_sysrq at ffffffff9e6a52e3
  #5 [ffffa9c500d0bd38] write_sysrq_trigger at ffffffff9e6a5b28
  #6 [ffffa9c500d0bd50] proc_reg_write at ffffffff9e1691b9
  #7 [ffffa9c500d0bd70] vfs_write at ffffffff9e0af87f
  #8 [ffffa9c500d0be10] ksys_write at ffffffff9e0aff83
  #9 [ffffa9c500d0be50] __x64_sys_write at ffffffff9e0b0039
 #10 [ffffa9c500d0be60] do_syscall_64 at ffffffff9ed399a9
 #11 [ffffa9c500d0bf50] entry_SYSCALL_64_after_hwframe at ffffffff9ee000e6
     RIP: 00007fd7ba71b214 RSP: 00007ffd1900fbc8 RFLAGS: 00000202
     RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd7ba71b214
     RDX: 0000000000000002 RSI: 000055b4326b7d60 RDI: 0000000000000001
     RBP: 000055b4326b7d60 R8: 0000000000000073 R9: 0000000000000000
     R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
     R13: 00007fd7ba7ff7a0 R14: 00007fd7ba7fd120 R15: 0000000000000000
     ORIG_RAX: 0000000000000001 CS: 0033 SS: 002b
 crash> quit